To protect themselves from marauding Allied destroyers, the Germans fenced off a channel close to the shore with a barrier of thousands of underwater mines. At salient points they mounted heavy, radar-directed cannon—some as big as nine and one-half inches in bore—to keep raiding destroyers pushed away from the mine-protected channel. The mine fields worked. Deep-draft destroyers did not dare chase Axis vessels too close to the beach. The shallow-bottom PTs skimmed over the top of the mine fields, however, so the Germans countered by arming many types of small ships as anti-PT boats. They took over a type of Italian warship called a torpedo boat, but actually a small destroyer, fast and heavily gunned, eminently qualified for PT-elimination work. Night patrols became lively, with PTs harrying Axis coastal shipping and the Germans hunting them with E-boats and armed minesweepers, torpedo boats and F-lighters. The first brawl after the PTs set up base on Sardinia and Corsica came on the night between October 22nd and 23rd. Three PTs, under the indefatigable Lieut. Dubose, sneaked up on a cargo ship escorted by four E-boats and minesweepers. The PTs fired a silent spread of four, and the cargo ship disappeared in a violent blast. Lieut. (jg) T. L. Sinclair was lining up his 212 to work a little more destruction, when a wobbly out-of-control Mark VIII torpedo from another PT flashed by under his stern. “How many have you fired?” Lieut. Dubose asked Lieut. Sinclair by radio. “None yet. I’m too damned busy dodging yours.” Between Giglio and Elba, in the Tuscan Archipelago, on the night between November 2nd and 3rd, two PTs, under Lieut. Richard H. O’Brien, made a torpedo run on a subchaser and blew a satisfactorily fatal hole in the hull with a solid hit. The stricken vessel went down, all right, but it went down fighting, and one of the last incendiary bullets from the dying ship bored through the gasoline tank of the 207, touching off an explosion that blew off a deck hatch. Flames as high as the radar mast shot through the open hatchway. A radioman turned on a fire extinguisher, threw it into the flaming compartment, and slammed down the hatch again. Miraculously, the fire went out. Early in November, Lieut. Commander Barnes, who had been doing some deep thinking about the war against F-lighters, came up with a new tactical idea. His reasoning was: PTs are radar-equipped, hence better than British boats at finding enemy vessels and maneuvering for attack; British torpedo boats use better torpedoes than American Mark VIIIs, for they are faster and carry heavier explosive charges; British gunboats have heavier firepower than PTs, for they usually carry at least six-pounder cannon and so can take on heavier opponents.